1. Field of the Invention
This invention generally relates to a linear motion guide assembly, and, in particular, to a linear motion guide assembly suitable for bearing a relatively large load.
2. Description of the Prior Art
FIGS. 4a and 4b illustrate the structure of a typical prior art linear motion guide assembly disclosed in the Japanese Pat. Appln. No. 62-9298 (Pat. Laid-open Pub. No. 63-180437). As shown, a pair of arc-shaped guide grooves is provided each at each edge of a rail, and a V-shaped guide groove is formed at each side surface of the rail. Such a structure is advantageous in reducing the overall height of the assembly. However, this structure has a poor capability in carrying a load which is directed vertically downward.
FIGS. 5a through 5e illustrate the structure of another prior art linear motion guide assembly disclosed in the Japanese Pat. Appln. No. 54-15911 (Pat. Post-examination Pub. No. 62-27287). In this structure, since the top guide grooves are provided at the top surface of the rail, it can sustain a relatively large load which is directed vertically downward. However, this structure is not capable of bearing a large load which is directed in a horizontal direction.
Thus, there has been a need to provide a novel linear motion guide assembly which can bear a relatively large load both in the vertical and horizontal directions.